ES2978366T3 - Hard metal insert for an agricultural device - Google Patents

Abstract

The invention relates to a carbide insert (1) for an agricultural implement, for example a hoe or a mower blade, which has active cutting zones (2) acting in a cutting direction. According to the invention, teeth are provided between the active cutting zones (2) at least partially protruding from the active cutting zones in a plan view. (Automatic translation with Google Translate, without legal value)

Description

DESCRIPTION

Hard metal insert for an agricultural device

The invention relates to a carbide insert for an agricultural implement, for example a ploughshare or a mowing blade, which has active cutting regions which are effective in a cutting direction.

From US 2014/069249 A1 a metal cutting insert for an agricultural device is known, which has cutting-active regions, which are effective in a cutting direction, with teeth being provided between the cutting-active regions at least partially, which in a plan view protrude beyond the cutting-active regions.

Agricultural equipment is often equipped with blades for various purposes. Blades can serve different purposes, for example, as in a cultivator tip, to break up soil to a predetermined height to make the soil workable, but also to chop straw, separate bales or otherwise enable cutting.

The active cutting elements required for this have been made of steel for many decades. Recently, the corresponding steel wear parts have been equipped with carbide to increase their longevity many times over. Although the purchase costs are much higher, these higher purchase costs pay off over the service life of the wear part. Thus, when taken into account in terms of purchase costs, the durability of wear parts equipped with carbide for agricultural implements is generally higher.

Depending on the intended application, various solutions have already been proposed for equipping individual agricultural implements and elements, such as ploughshares or chopping knives, with carbide individually and in a geometry-specific manner. However, this requires a specific application development for each individual field of application, which must take into account the geometry of the respective wear part. In addition, there is an interest in further increasing dimensional stability in order to achieve even greater productivity with regard to the service life of a cutting wear element.

The objective of the invention is to perfect an insert of the type mentioned at the beginning in such a way that it satisfies the above requirements.

This objective is achieved by the features of claim 1.

This solution provides an insert which can be mounted, for example, on a cultivator tip, a ploughshare, a mowing blade or another component, which may be part of a larger device. Two advantages are achieved in this respect in particular: on the one hand, preventive measures are taken to maximise the longevity of the insert, largely independent of the specific purpose of use. The protruding teeth serve in this context to absorb, for example, impacts from stones, more solid soil or generally hard materials, and thus protect the recessed cutting areas which do not intervene until later. For example, if a stone hits one or more teeth, then these teeth are subject to wear, but not the cutting areas which do not intervene until later. On the other hand, such an insert can be attached, for example, by means of a material bonding to virtually any component which is required for cutting in agriculture. This ranges from soil processing to straw cutting. This means that it is practically a universal insert, which once developed can be used for a large number of agricultural machining equipment. This also enables efficient and less intensive stocking and storage, which in turn enables rapid replacement.

According to the invention, for the reasons explained above, it is provided that in a plan view of the insert at least individual cutting-active regions are located completely behind the adjacent teeth. If the cutting-active regions are arranged completely behind the teeth, they cannot be damaged by hard material.

It can be provided that the teeth are set higher than the cutting edges of the active cutting areas. Since the teeth are subject to impacts from stones or generally hard materials, the teeth are also subject to wear, which is not insignificant. This is taken into account by a raised configuration of the teeth, so that on the front side of the insert with the active cutting areas running on one side and the teeth on the other side there is excess material in the area of the teeth.

The active cutting zones are usually arranged between the teeth. However, the teeth themselves can also be active for cutting if they are designed with appropriate cutting edges. However, this is not generally necessary, since the teeth are intended for another purpose.

The number of teeth can be arbitrary. Typically, at least three teeth are provided, which separate active cutting areas from each other. The tooth spacing is selected in this respect as well as in general so that two or more teeth can be hit by an impact, for example by a stone. In this respect, the teeth can be arranged at the same distance from each other in each case. However, it is also possible to provide different distances for the teeth, which can follow a certain pattern, for example. It is possible to provide shorter and longer distances alternately or to design the tooth spacing in the center of the insert differently than in the edge regions of the insert.

The active cutting areas are recessed, but can have any height contour. For many applications, it is advantageous if the individual active cutting areas are represented as straight lines in a front view, so that the entire active cutting area is at the same height. The individual active cutting areas are at the same height in a front view, so that conceptually, when viewed from the front, a continuous cutting line is obtained, separated only by the teeth.

The insert is made of hard metal, which does not necessarily require it to be formed from a single piece, although the latter is simpler from a production technology point of view and is therefore preferred.

The insert can basically be made of any carbide. However, carbide grades with approximately 80 percent by weight (hereinafter: % by weight) to 95 percent by weight and a binder metal, preferably cobalt, in an amount of from 5 to 15 percent by weight, preferably from 7 to 13 percent by weight, in particular from 8 to 12 percent by weight, have proven to be suitable, with tungsten carbide having an average grain size in the range of from approximately 1.5 | im to 5 | im, in particular from 2.0 | im to 3.0 | im. The corresponding carbide grades have proven to be suitable for cutting performances in the agricultural sector. It can also be provided that the insert is coated. Coatings by means of CVD or PVD processes are considered for this purpose. Coatings can be, for example, Ah-xTixN coatings. The corresponding coatings can have a layer thickness of, for example, up to 15 |im. Coatings with alternating coating layers of different compositions are also possible.

In accordance with the advantages set out above, an insert according to the invention is used in an agricultural implement. In the case of the agricultural implement, this may be, for example, a straw chopping blade, a mowing blade, a carrot topping blade, a crusher hammer, a straw rotary blade, blades for forwarders, round balers and feed mixers, a ploughshare or a disc for a disc harrow.

Additional features, advantages and effects of the invention are obtained from the exemplary embodiments explained below. The drawings, to which reference is made in this respect, show:

Figure 1 shows an insert according to the invention in a plan view;

Figure 2, a part of a front side view of the insert of Figure 1;

Figure 3, an enlarged representation of section III in Figure 1;

Figure 4, a complete front side view of the insert of Figure 1;

Figure 5, a section along the V-V line in Figure 1;

Figure 6, a section along the line VI-VI in Figure 1;

Figure 7, a straw chopping blade;

Figure 8, a cultivator's share;

Figure 9, a disc for a disc harrow;

Figure 10, a blade for a round baler.

An insert 1 according to the invention is shown in Figure 1. The insert 1 is constructed from a single piece, but it is also possible for the insert 1 to be made up of several pieces with the same geometric shape. In the case of the insert 1, but also in general, it is advantageous if it is configured from a single piece.

The insert 1 is made of a carbide. In the case of a carbide, it can be a conventional carbide. Preferred are those grades which have an approximately medium size, i.e. which do not correspond to the classical definition of a fine grain, but which are not too coarse either. In practice, it has proven to be particularly advantageous if the average grain size of the hard substance particles, for example tungsten carbide, is in the range from 2.0 |im to 3.0 |im. The commonly used cobalt is preferably used as the binder metal, although binder metals based on nickel and/or iron are also possible. Combinations of the latter metals with cobalt are also possible, as well as a combination of cobalt with nickel and iron as the binder metal. Typically, the proportion of the hard substance particles such as tungsten carbide is in the range from 88% by weight to 95% by weight, in particular approximately 88% by weight to 92% by weight. The remainder is comprised, for example, of the binder metal cobalt. Of course, it is also possible that at least part of the tungsten carbide is replaced by other hard substance particles, for example titanium carbide.

The insert 1 has a front side 11 and an opposite rear side 12. The front side 11 and the rear side 12 are connected to each other in the plan view of the insert 1, which can be seen in FIG. 1, by connecting sides 13. Rounded corners 14 are provided at the transition from the rear side 12 to the connecting sides 13, although the corresponding transitions can also be angled. The rounded corners 14 have, however, proven to be suitable for the fastening of the insert 1 to an agricultural implement or a component thereof, which will be explained later. On the front side 11, the insert 1 has an approximately zigzag structure in a plan view. The zigzag structure is defined by cutting-active regions 2 and teeth 3. The teeth 3 are basically arranged in each case between the cutting-active regions 2. The zigzag structure can also be terminated on the outside by additional teeth 3. In this case, the outermost teeth 3 arranged on the outside are not followed by any additional cutting-active regions. In the embodiment variant shown in Fig. 1, however, each tooth 3 is in each case surrounded by two adjacent cutting-active regions 2.

As can be seen particularly clearly in the plan view in Fig. 1, the cutting-active regions 2 are arranged in a recessed manner relative to the teeth 3. If the insert 1, which is attached to an agricultural implement or to a component for an agricultural implement, which is in turn attached to the agricultural implement, is now effectively moved in the direction of a cutting direction S, the teeth 3 serve as impact zones against which, for example, stones can collide, but which do not reach the cutting-active regions 2. For this purpose, the teeth 3 are arranged with a distance from one another of approximately 5 mm to 25 mm, preferably 6 mm to 20 mm. The actual distance depends on the expected loads or the material to be machined and can be adjusted accordingly, for example for the machining of earth or for cutting straw. The teeth 3 thus also absorb occasional impacts, so that the cutting-active regions 2 are correspondingly protected.

As can be seen from the front view of Figure 2, the offset teeth 3 are configured to be raised relative to the cutting-active regions 2 and are therefore to be regarded as material reinforcement. This material reinforcement of the teeth 3 reflects a twofold operating principle: While the recessed, cutting-active regions 2 are to enable material cutting for as long as possible, the teeth 3 are to suppress impacts and other disturbances that substantially reduce the durability of the cutting-active regions. A very good durability can be achieved by this configuration of the insert 1. Since the teeth 3 are also configured with an elevation, for example an elevation of up to 1 mm relative to the cutting-active regions 2 as a baseline, the teeth 3 can be kept relatively narrow without impairing function. Typically, the width of the teeth 3 along the zigzag structure (see Figure 1 or Figure 2) is less than 30%, preferably less than 25%, particularly preferably less than 20%, of the length of an active cutting region 2 located therebetween.

As can be seen in Fig. 2, the insert 1 on the front side 11 is pointed in thickness, which is advantageous for a good cutting action. In the region following it, the insert 1 is shaped with a constant thickness. From Fig. 2, in particular, the raised configuration of the teeth 3 with respect to the cutting-active regions 2 can also be seen, which is once again shown in Fig. 4 for a complete front view.

3 shows a fragment III according to FIG. 1. As can be seen, the cutting-active region 2 shown, which is followed by two teeth 3, is substantially V-shaped. In this respect, it can be advantageous, as shown, to avoid occasional corners by rounding. This reduces the risk of punctual breakage of the insert 1, because the stress peaks are reduced. In FIG. 3, the cutting-active region 2 forms cutting edges 4, which produce the actual cutting performance of the insert.

In Fig. 5 a section along the line V-V is shown in Fig. 1, in Fig. 6 a corresponding section along the line VI-VI, also in Fig. 1. Through these sectional representations it can be seen once again that the insert 1 converges conically on the front side 11, the teeth 3 being configured with respect to the active cutting regions 2 with an elevation of more material.

An insert 1 according to the invention can be used in any component for agricultural implements or also in these implements, for example as a straw chopping knife, a mowing knife, a carrot-topping knife, a shredder hammer, a straw rotary knife, a knife for forwarders, round balers and/or feed mixers, as a tillage share or in a disc for a disc harrow. Some exemplary embodiments are shown below. For example, Fig. 7 shows a straw chopping knife, Fig. 8 a cultivator share, Fig. 9 a disc for a disc harrow and Fig. 10 a knife for a round baler. All exemplary embodiments have in common that an insert 1 according to the invention is used. In the exemplary embodiments, a large number of inserts 1, which are effective in a cutting direction S, are provided for in each case, although not necessarily. The inserts 1 are usually arranged at an angle of attack relative to a base of the respective tool of from about 5° to 25°, in particular from 10° to 20°. The inserts 1 can be attached to the corresponding components or tools by welding. It is preferred that the insert 1 is at least minimally spaced from the insert 1 in each subsequent case. However, it is also possible for the individual inserts 1 to be arranged one after the other or in contact with one another. It is particularly advantageous, regardless of the type of tool or component, if corresponding recesses are provided therein for receiving one or more inserts 1, into which the inserts 1 can be inserted. Fastening can take place by gluing materials, in particular by welding.

A significant advantage of an insert 1 according to the invention is, in addition to a high durability, that, as can be seen in particular also from the exemplary embodiments according to Fig. 7 to Fig. 10, the insert 1 can be used in virtually any agricultural implement or component thereof. This considerably reduces storage, since the same parts can always be used.

Claims (8)

i. Insert (1) made of hard metal for an agricultural implement, for example a ploughshare or a mowing blade, which has cutting-active regions (2) which are effective in a cutting direction (S), with teeth (3) being provided between the cutting-active regions (2) at least partially, which in a plan view protrude beyond the cutting-active regions (2), the cutting-active regions (2) being at the same height in a front side view. 2. Insert (1) according to claim 1, characterized in that in a plan view at least individual cutting-active regions (2) are located completely behind the adjacent teeth (3). 3. Insert (1) according to claim 1 or 2, characterized in that the teeth (3) are configured elevated with respect to cutting edges (4) of the active cutting regions (2). 4. Insert (1) according to one of claims 1 to 3, characterized in that the cutting-active regions (2) are configured in a plan view with an approximately V-shaped development. 5. Insert (1) according to one of claims 1 to 4, characterized in that at least three teeth (3) are provided, which separate active cutting regions (2) from each other. 6. Insert (1) according to one of claims 1 to 5, characterized in that the insert (1) is configured in one piece. 7. Insert (1) according to one of claims 1 to 6, characterized in that the insert (1) is coated. 8. Agricultural device with an insert (1) according to one of claims 1 to 7.